In the automated production of frozen meat products, it has become the industry practice to manufacture the patties using high speed machinery in a centrally located production plant and to ship the patties in a frozen condition to the point of use; a restaurant or cafeteria or other food outlet such as a fast food restaurant. With the rapid growth of this industry, the use of meat patty forming machines has proliferated to the point where it has become almost essential to the successful operation of a high speed frozen meat plant in which frozen patties are produced. Some of the most modern of these machines operate at production speeds of 4,000 pounds or more per hour on a single line. After the patties are formed, they are conveyed directly into a freezing tunnel and frozen, for example, by surrounding them with liquid nitrogen. The frozen patties are then placed in cartons or boxes and are stored in the frozen condition for shipment to the restaurant. Typical equipment of this kind is illustrated by U.S. Pat. Nos. 4,182,003, 4,054,967 and 4,137,604.
While this equipment has been highly successful in producing meat patties at high speed, the results have not been entirely satisfactory particularly in better restaurants where high quality and slight nuances of flavor or texture become important. In these better quality restaurants, the conventional pressure formed patties are not perceived to have anything of value beyond those found in a fast food restaurant. Thus, equipment of the type described and illustrated in the patents produces patties having a flat, circular or square shape with almost perfectly smooth upper and lower surfaces. Many consumers believe these flat discs of meat are monotonous and unnatural and therefore are not especially appetizing. In addition, partly because they are relatively thin, usually about 1/4" thick, but more importantly because they are circular or square in shape, all portions of the patty cook to about the same consistency. The result is that there are few variations in the eating taste and texture from one part of the finished patty to the other and the fat and moisture exuded during the cooking process which most people perceive as adding to the flavor of the finished meat can easily run off and be lost. Thus, the square or circular shaped meat patties with smooth upper and lower surfaces formed by the internal metal die surfaces of the machines are thought by many people to be rather insipid both in their eye appeal and in their taste and bite. Another problem with the die formed patties of the type described above is that they tend to have a relatively rubbery, almost resilient texture that many people find undesirable. Moreover, patties of this kind tend to become thinner as they cook and some of them shrink down to such an extent that the consumer is likely to wonder how a hamburger could be made so thin.
Attempts have been made for example as described in U.S. Pat. No. 3,060,494 for molding food into the form of a steak by forming the meat in a metal collar or ring similar to a cookie cutter with a separate shaped ring for the bone. This is, however, slow and each finished piece of meat produced has the same shape as all the others. By contrast with the present invention, it is an objective to find a way to give each piece a different and unique shape while operating at production speeds of around 2 tons an hour or more. Other equipment has been previously proposed as described in U.S. Pat. No. 3,550,190 for folding steaks along a center line but such steaks, depending upon their composition, can fall apart or delaminate at the contact line between the two layers. Moreover, the process forms a rather long piece of meat with pointed ends similar to a pastry turnover. This shape is unsatisfactory for many meat products particularly meat patties such as hamburger patties toward which the present invention is directed.
Achieving precise weight control of each patty is extremely important. In handmade patties there is, of course, no control. With machine made patties, control is possible provided subsequent operations do not change the piece weight, e.g., due to meat fragments falling off. Thus a 2% difference after a day of running at 4 tons per hour can make a difference of 1,280 lbs. of meat lost assuming the error is cumulative as an excess.
In overcoming the foregoing and related deficiencies of the prior art, this invention then comprises the features hereinafter fully described and particuarly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.